[133] Even as
NASA was being formed, the stable of American sounding rockets was
impressive. There were small (Deacon, Cajun, Arcon, Arcas), medium
(Aerobee, Aerobee-Hi), and large (Viking) rockets. Viking had been
designed to replace the V-2, which was no longer used after the
test program ended in 1952. There were rockets using solid
propellants (Deacon, Cajun, Arcon, Arcas) and rockets using liquid
propellants (second stage of Aerobee, Viking). Multistage
combinations (Nike-Deacon, Nike-Cajun, Aerobee) achieved higher
altitudes than could economically be attained with single-stage
rockets. Rockets had been launched from balloons, from aircraft,
and from launchers aboard ships at sea. These sounding rockets and
the high-altitude research program that went with them provided
NASA with an immediately on-going component of its space science
program.1

A similar situation existed with respect
to the larger vehicles needed for launching spacecraft into orbit.
The reentry test vehicle Jupiter C-which launched America's first
satellite, Explorer
1, and which used the Redstone
missile as its first stage-gave rise to a first group of what were
called Juno space launch vehicles. Later versions of Juno used the
more powerful Jupiter intermediate-range ballistic missile as the
first stage.2 The Redstone, which was created for the Army by the
von Braun team and in which one could detect a distinct V-2
ancestry, was on hand and was used for America's first suborbital
manned flights.3 The Vanguard IGY launch vehicle, which used
derivatives of the Viking and Aerobee sounding rockets as its
first and second stages, was also available.4 NASA took over Vanguard from the Naval Research
Laboratory and completed the program, after which the Vanguard
first stage was retired; but the upper stages were combined with
the Air Force's Thor to create the Thor-Delta, or simply Delta,
launch vehicle, which from the very start was one of the most
useful of the medium-sized combinations.5 In 1958 the Air Force's Atlas was the most powerful
U.S. rocket that could be quickly pressed into service as a
[134] space launcher. To it was assigned the
launching of The first American astronauts to go into
orbit.6 Atlas eventually became the main stage of
Atlas-Agena and Atlas-Centaur, multistage launch vehicles used to
put multiton payloads into space.

The imposing presence of the Soviet Union
in space following the launching of the first Sputniks and the
substantial lead it apparently had over the U.S. in payload
capability generated a sense of urgency to develop very large
payload capabilities. But with the variety of vehicles already in
its stable or imminent, the United States clearly was not going to
have to start from scratch. Indeed, had the country been willing
to use the von Braun rockets for the IGY satellite program, the
first satellite in orbit could well have borne a "made in America"
stamp. At any rate, even this partial survey of the situation at
the time NASA got going shows how deep in the rocket and missile
work of the 1950s lay some of the roots of the subsequent space
program.

Of course, along with the missiles and
rockets available to NASA and the military were associated
facilities and equipment already in operation. Launch ranges
existed in Florida, California, New Mexico, and Canada. Tracking
and telemetering stations, strategically located in the U.S. and
elsewhere, were working. Vanguard Minitrack network of
radio-tracking and telemetering stations for operating with the
IGY satellites spanned the globe and provided a nucleus on which
to build for an enlarged program of the future. IGY optical
tracking stations also girdled the globe and were immediately
available for photographic and visual tracking of spacecraft that
were large enough to be detected by such means. To produce all
these a substantial component of American aerospace, electronics,
and other industry had been employed, generating hardware and
acquiring an experience ready to be used for tackling the
challenges that lay ahead.7

One of the first tasks facing NASA in the
fall of 1958 was to determine what additional launch vehicles
would be required to accomplish the space missions planned for the
program. While most of the launchers would derive from military
hardware, some, especially for the manned spaceflight program,
would have to be built from scratch. So, too, would the space
craft for the science, applications, and manned spaceflight
missions.